I plan to determine what macromolecular interactions are responsible for maintaining long range DNA folding found in chromosomes. Membrane-associated chromosomes isolated from Escherichia coli will be treated with restriction nucleases, and the free DNA will be separated from membrane-bound DNA. The distribution of specific DNA restriction sequences between the two fractions will be measured to determine whether the membrane-associated DNA sequences are random or not and hence provide information about whether the membrane DNA loops are static or dynamic structures. Involvement of the DNA loops with chromosome replication and transcription will be assessed by the chromosomal distribution of pulse-labeled DNA and RNA after restriction nuclease treatment of the chromosome. The protein, RNA, and DNA moieties from subchromosomal membrane-DNA complexes will be characterized, their interactions examined, and structural alterations will be related to functional deficiencies of mutants.